Leakproof inflatable articles



Sept. 20, 1955 M. MIZRACH ET AL LEAKPROOF INFLATABLE ARTICLES Filed Aug.7, 1955 ATTORNEY n7 0/ 8 n. q 9 My 00. Pag 7 I w 'ments of the side.

2,718,014 Patented Sept. 20, 1955 United States Patent Cfifice 2,718,014LEAKPROOF INFLATABLE ARTICLES Murray Mizrach and Jordan Mizrach,Brooklyn, and

Our invention relates to collapsible and inflatable articles and may be"particularly incorporated in wading pools for children.

An object of our invention is to protect wading pools or other inflatedarticles against leakage of air or of water or of both.

Other objects are to attain this protection by simple, automatic andreliable means, and to provide leakproof inflatable articles that can bemade of resiliently stretchable plastics.

Still other objects and advantages will appear from the followingdescription of exemplifying embodiments of our invention, from theappended claims and from the accompanying drawing in which:

Fig. 1 shows a top view of a wading pool forming an exemplifyingembodiment of our invention.

Fig. 2 shows a side view of the same embodiment.

Figs. 3, 4 and 5 show cross-sections of three diiferent modifications ofthe embodiment shown in Figs. 1 and 2, these cross-sections being takenalong the line 33 in Fig. 1 through a broken off portion of the wadingpool, and being represented on a larger scale than Figs. 1 and 2, thethicknesses of the walls being exaggerated for the sake of clearrepresentation.

The wading pool shown in the drawing has a flat bottom 1 and acircularly closed side 2-extending from the circumference of the bottomup and surrounding a space adapted for being filled with water. Theouter shape of the side 2 is the same in all three modifications whichdiffer only in the inner structure. In all three cases, the sidecomprises three ring-like compartments positioned over each other,connected with each other and, each, having a substantially circularcross-section and a doubled wall formed by an outer wall surrounding aninner wall. Instead of three compartments, there may be two or any othernumber of compartments.

One or more valves 4 pass through both walls of the side 2 and serve forinflating or deflating the compart- These valves may be of any known andsuitable structure and have tubular air ducts tightly passing throughthe walls of the side 2. The outer opening of each valve 4 may be closedby a cap 5.

In the modification shown in Fig. 3, each compartment has an inner airspace 6 surrounded by an inner Wall 7 and an outer wall 8. Betweenadjacent compartments, wall portions 9 are located which form integralextensions of the walls 8 of both adjacent compartments and which arereinforced, for example, by making the portions 9 thicker than the walls8. The inner walls 7 form integrally united extensions of the sameportions 9, and are spaced from the walls 8, except where they areconnected with the portions 9.

The walls 7 and 8 are made of thin, highly and resiliently stretchableplastic material whereby they will expand under the influence of innerpressure and will collapse when no inner pressure exists. The portions 9and the bottom 1 may be made of the same material.

The spaces between the walls 7 and 8 are filled with a congealableliquid 11 which closes automatically and instantly any hole or openingthat may be made in these walls, for example, by accident or by childishmischief. Liquids of this type are well knownand have been used in: theinner tubes of automobile tires where the liquid fills a small portionof the inflated air space and is applied to the wall of the tube bycentrifugal force. We have found that such a liquid can make astationary infiated article leak-proof without centrifugal action if theliquid is confined and compressed between two expandable walls, that thesimultaneous expansion of both walls and the compression of the liquidcan be readily produced by inflation of the inner wall, and that it isof advantage if the inflated air space does not contain any liquid. Wehave further found that such a double walled article can be shaped toform a receptacle for water, and that the congealable liquid in thedoubled wall will protect the receptacle against leakage both of air andof water.

In the modification described above, the inner and outer walls form oneunitary body.

The second modification shown in Fig. 4 is similar to the firstdescribed modification and may have outer walls 18 which aresubstantially identical to the walls 8 and which are interconnected byre-inforced portions 19. The inner walls 17 do not extend from theseportions, but form separate bodies positioned substantiallyconcentrically within the walls 18. Thereby the congealable liquidsurrounds the air spaces 16 at all sides.

Both in the first and in the second modification, the air spaces may beseparated as exemplified by Fig. 3 or may communicate through channelsas exemplified by Fig. 4. Such channels may be formed by tubes 13 whichpass tightly through the inner walls of adjacent compartments andthrough the wall portion 19 between these compartments. In the caseillustrated by Fig. 3, one valve 4 is provided for the inflation of eachair space 6. In the case illustrated by Fig. 4, only one valve 4 isrequired and may serve to inflate all air spaces 16 simultaneously.

In the third modification shown in Fig. 5, the outer walls 28 of thecompartments are connected by thicker wall portions 29 which surroundnarrow passages connecting adjacent compartments. The inner walls 27 aresimilarly connected by thicker portions 25 which are spaced from theportions 29 and surround narrow passages connecting the air spaces 26.The outer walls form one unitary body, and the inner walls form anotherunitary body. The air spaces communicate with each other, and also theliquid-filled spaces between the inner and outer walls communicate. Onlyone valve 4 is needed, and all compartments can be filled with liquid byone injection.

In each of the described cases, the manufacture of the article may befacilitated by making the same of several, suitably divided parts whichthen are united, for example by the application of heat and pressure,into the shown configuration in which the dividing lines do no moreappear. The co-ngealable liquid may be injected through the outer wallswhich are temporarily punctured for this purpose. After removal of thepuncturing injector, the punctured holes disappear immediately, the samebeing sealed by the congealing liquid.

The re-inforced wall portions connecting the compartments are much lessyielding than the other wall portions. Hence, when the air spaces areinflated, the resulting expansion of the walls is substantially limitedto these other portions.

We desire it understood that our invention is not confined to theparticular embodiments shown and described, the same being merelyillustrative, and that our invention may be carried out in other wayswithin the scope of the 3 appended claims without departing from thespirit of our invention as it is obvious that the particular embodimentsshown and described are only a few of the many that may be employed toattain the objects of our invention.

Having described the nature of our invention, what weclaim and desire toprotect by Letters Patent is:

1. An article of manufacture comprising a plurality of compartments,each having an outer and an inner wall surrounding an air space, bothsaid walls being made of thin collapsible and resiliently stretchableplastic material and, between them, including another space, and acongealable liquid filling said other space whereby inflation of saidair space presses said liquid against said outer wall and expands bothwalls, and channels connecting the air space of one compartment withthat of another compart ment whereby inflation of one compartmentinflates also the other compartment, said channels forming integralextensions of said inner walls and being spaced from said outer wallswhereby said spaces between said walls communicate.

2. An article of manufacture comprising a plurality of compartments,each having an outer and an inner wall surrounding an air space, bothsaid walls being made of thin collapsible and resiliently stretchableplastic material and, between them, including another space, and acongealable liquid filling said other spaces, said other spacescommunicating with each other whereby inflation of said air spacespresses said liquid under uniform pressure against said outer walls andexpands both walls of all compartments.

References. Cited in the file of this patent UNITED. STATES PATENTS755,747 Coile, Mar. 29, 1904 1,429,031 Harder Sept. 12, 1922 1,451,536Davis et al. Apr. 10, 1923 2,443,440 Alvarez June 15, 1948 2,657,729Hardman et a1 Nov. 3, 1953 FOREIGN PATENTS 22,301 Great Britain Feb. 19,1903

